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| Titel |
Turbulence structure produced by coastal wave breaking |
| VerfasserIn |
J. M. Redondo, O. B. Mahoub, R. Alami |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250022167
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| Zusammenfassung |
| Experimental results of waves propagation in large flume for both regular and
irregular waves are presented. Time series of waves propagation were carried out measuring turbulent velocities
at 0.4 m below
water surface by means of a velocimeter SONTEK3-D. The probability
distribution functions of the velocity fluctuations are analyzed and non Gaussian
distribution is found both for regular and irregular waves. Finally, the behavior
of the two energy spectrum components are presented. indicating that irregularity
is an important source of turbulence. We describe detailled measurements of
the velocity characteristics, including the structure functions of the wave induced
turbulence at the CIEM large wave tank, and compare these measurements with
lagrangian velocimetry and dispersion measurements of tracers in the wave induced
turbulent environment. Especially for irregular wave transformations due to breaking in shallow waters. In contrast, regular wave transformations can be easily generated
and investigated in the laboratory due to the capacity of instrument to generate
waves with a given height and period. On the other hand, there is also the possibility to
generate irregular waves in the laboratory by varying the wave height and period. The
control of the height and period characteristics may help to understand the mechanism
of wave energy dissipation. Consequently, some important informations on the structure of the turbulent cascade and its role on sediment entrainment and diffusion is important
approximations which can play a key role to investigate the propagation of sand with either regular/irregular
and breaking waves in real coastal and beach flows.
We also compare the results of laboratory experiment concerning regular
and irregular waves of different heights and periods.
All experiments were
carried out by means of a sonic velocimeter SONTEK3-D in a water channel 100 m of long
within the European Union Project SPAN-WAVE.. |
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